Technical Field
The present invention relates to a light emitting apparatus with a light emitting diode (LED) device as a light emitting source.
Related Art
Since an LED device is a semiconductor device, it has a longer operating life and superior operating characteristics, is small-sized, has high light emission efficiency, and exhibits a bright luminescent color. As the results, an LED device has been widely used recently as a backlight for a color display apparatus, a flashlight apparatus, an illumination, or the like.
Among others, a reflection-frame-type light emitting apparatus has recently been proposed, in which the surroundings of an LED device are covered with a reflective resin such as a white resin for improving the upward light emission efficiency by reflecting upward the light emitted laterally by the LED device, and a reflection frame having an aperture is combined above the LED device for condensing further the light upward.
As an example, a reflection-frame-type light emitting apparatus described in JP2009-283988A will be described below. For easier understanding, drawings have been simplified to the extent that the spirit of the invention is not jeopardized, and the names of parts have been changed to conform to those used in the present specification.
FIG. 28 is a cross-sectional view of a light emitting apparatus 100 described in JP2009-283988A. The light emitting apparatus 100 has a circuit substrate 107, which has wiring electrodes 105a and 105b on the upper side, side electrodes 105c, and power electrodes 105d on the back side. The wiring electrodes 105a and 105b are connected through the side electrodes 105c with the power electrodes 105d. On the upper surface of the circuit substrate 107, an LED device 101 is die-bonded to the wiring electrode 105a, and an upper electrode of the LED device 101 is connected through a wire 104 with the wiring electrode 105b. The LED device 101 and the wire 104 are covered with a translucent encapsulation resin 103 (a transparent resin or a fluorescent resin). Further, a reflection frame (reflector) 109 for reflecting and collecting the emitted light from the LED device 101 is fixed by adhesion or the like, around a mounting area of the LED device 101 on the circuit substrate 107.
FIG. 29 is a cross-sectional view of another light emitting apparatus 200. In the light emitting apparatus 200, an LED device 201 is flip-chip mounted at the center of a circuit substrate 207 having wiring electrodes 205a and 205b. A reflection frame 209 (a horn reflector), which is made of a reflective white resin or the like and opens wider upward, is fixed around the LED device 201. Further, the surroundings of the reflection frame 209 is sealed with an encapsulation resin 206 composed of a black color resin or the like, and a phosphor layer 202 and a lens 233 are fixed at an aperture of the reflection frame 209 by the encapsulation resin 206. The central axis of the lens 233 and the central axis of the LED device 201 are aligned in the light emitting apparatus 200, and therefore the light emitted vertically upward from the LED device 201 and the light emitted laterally from the LED device 201 and reflected upward by a reflection surface of the reflection frame 209 are collected favorably by the lens 233 and emitted upward.